It's back to the drawing board for coders at Microsoft, Google, Adobe, Mozilla, and Oracle after entrants in the annual Pwn2Own contest waltzed off with over half a million dollars in prizes for exploiting security holes in popular software.

At this year's CanSecWest security conference in Vancouver, contestants had a choice of two hacking contests; the traditional Pwn2Own trial against Internet Explorer 10, Firefox, Chrome, Java, and Adobe's Reader and Flash, plus Google's own Pwnium contest – which this time focused on cracking Chrome OS.

HP provided some of the sponsorship for Pwn2Own this year with Google, and Brian Gorenc, manager of vulnerability research for HP's Zero Day Initiative, told The Register that the company had paid out $480,000 in cash to the crackers, along with laptops and subscriptions that brings the total prize pot to over half a million dollars.

"It's a really good investment," he explained. "It puts us on the cutting edge of security research and we get to see the latest and greatest attack techniques, which we can then feed into our other security products," Gorenc said.

In the first day of cracking on Wednesday, Internet Explorer 10, Firefox, Chrome, and Java all fell prey to the skill of the security researchers, and on Thursday Flash, Adobe Reader, and IE 10 on the Surface Pro were successfully hacked (despite some frantic last-minute patching) – with some of the hacks beating expectations at what was possible.

"VUPEN Security's crack on IE 10 running on Surface Pro was an eye-opener," Gorenc said. "The vulnerability was so elegant it didn't even crash the browser. They launched the process from outside the sandbox so the user wouldn't even know if they had been hacked."

Meanwhile, two researchers from MWR Lab managed to subvert Google's Chrome browser so completely that they compromised the entire target system it was installed on, which Gorenc praised as "highly skilled."

But there will still be a lot of smiles down at the Chocolate Factory after Google appears to have come to the end of its Pwnium challenge against Chrome OS without having to pay a penny from the $3.14159m prize pot that it put up for grabs.

"Pwnium 3 has completed and we did not receive any winning entries. We are evaluating some work that may qualify as partial credit," Google told El Reg in an emailed statement. "Working with the security community is one of the best ways we know to keep our users safe, so we're grateful to the researchers who take the time to help us in these efforts." ®